Cascalog debugging helper

debug-flows.clj

(defn compile-and-dot
  "Debugging helper.  Compile a flow, print the steps, and write out the DOT
files for the flow operations and MR job steps."
  [& args]
  (let [^Flow flow (apply c/compile-flow args), name (.getName flow),
        flow-path (str name "-flow.dot"), steps-path (str name "-steps.dot")]
    (returning nil
      (doseq [step (.getSteps flow)]
        (prn step))
      (doto flow
        (.writeDOT flow-path)
        (.writeStepsDOT steps-path)))))

(defmacro debug-flows
  "Generate debugging information for flows run in the argument body."
  [& body]
  `(with-redefs [?- compile-and-dot]
     ~@body))